1. Field of the Invention
The present invention relates to a light tube, and more specifically, to a light tube having microstructure regions respectively formed on a roof portion and two side arm portions of a transparent cover.
2. Description of the Prior Art
In recent years, for achieving the environmental protection and energy saving purposes, a cold cathode fluorescent lamp has gradually been replaced by a light emitting diode tube utilizing at least one light emitting diode as a light source. However, the light emitting diode tube only has an illumination angle of about 120° due to the limited light emitting angle of the light emitting diode (about 120°), which is far less than that of the cold cathode fluorescent lamp, so as to restrict the illumination application of the light emitting diode tube.
In the prior art, the design of utilizing an approximately planar cover to replace a semi-circular cover for providing approximately planar illumination has been developed to increase the light emitting angle of the light emitting diode tube. However, due to uneven brightness distribution on the approximately planar cover caused by different light paths from the light emitting diode to the approximately planar cover when light emitted by the light emitting diode is incident into the approximately planar cover, the aforesaid design usually makes the light emitting diode tube have a poor visual effect.